Coiled tubing and other heavy equipment is generally transported by roadway on multi-axle trailers. Due to greater well depths, coiled tubing lengths needed to complete most well servicing jobs have also increased. Trailer lengths have been extended to offer more axles to allow even more equipment or coiled tubing to be transported to jobsites. By its nature, coiled tubing equipment is heavy and requires specifically designed trailers to transport such heavy loads. However, today's longer transport trailers have encountered highway and roadway weight per axle restrictions and maneuverability, e.g., turning, restrictions. In some circumstances, highway and roadway weight restrictions are such that additional axles, or equipment with additional axles that attaches to either the front or rear of the trailer, must be used to lower the weight per axle. However, additional axles and equipment limit a trailer's turning ability. Certain trailers are designed with axles that “passively” turn in the direction of the tractor pulling the trailer, but the axles can only be straightened manually. What is needed is an improved transport trailer capable of different axle weight configurations and capable of automatically straightening the wheels on one or more axles while in reverse.
Embodiments disclosed herein relate to a multi-axle transport trailer including a plurality of axles, and a suspension comprising air bags associated with each axle, the air bags in communication with an air source, wherein air bags associated with different axles are capable of having different air pressures therein, and a steering system associated with at least one axle, the axle including a tie rod connected between wheels on both ends of the axle, the steering system comprising cylinders configured to articulate the wheels, and a sensing device configured to monitor movement of the tie rod and facilitate actuating the cylinders to turn the wheels.
Other embodiments disclosed herein relate to a method of operating a multi-axle transport trailer in reverse, the trailer comprising suspension air bags in communication with an air source and associated with each axle, and a steering system associated with an axle including a tie rod connected between wheels on both ends of the axle and a control valve configured to operate cylinders to articulate the wheels. The method includes transmitting a signal to the control valve when the trailer is moved in reverse, reducing air pressure within air bags associated with axles having wheels to be articulated, and actuating the cylinders to articulate the wheels in a direction determined by a sensing cylinder coupled to the tie rod.
Yet other embodiments disclosed herein relate to a multi-axle transport trailer comprising a plurality of axles, and air bags associated with each axle, the air bags in communication with an air source, wherein air bags associated with different axles are capable of having different air pressures therein.
Still further embodiments disclosed herein relate to a steering system associated with at least one axle of a multi-axle transport trailer, the axle including a tie rod connected between wheels on both ends of the axle, the steering system including steering cylinders configured to articulate the wheels, a sensing cylinder coupled to the tie rod and configured to monitor movement of the tie rod, a first accumulator in fluid communication with a first end of the sensing cylinder, and a second accumulator in fluid communication with a second end of the sensing cylinder, and a switch configured to monitor pressure within the first and second accumulators, wherein increased pressure within either the first or second accumulator causes the switch to send a signal to actuate the steering cylinders in an appropriate direction to articulate the wheels.